why does running your hands under cold water reduce the stinging in your eyes from cutting onions?

Question

I know it works, since I do it a lot, but I have no idea how the hands are connected to the eyes in this particular way.

In: 2

Answer 1

Your tactile nervous system responds to pain, temperature and pressure. However, all of this information bottlenecks at the level of attention — only some of it gets through to further processing (the “focus”). So the feeling of coldness may be causing more “cold temperature signal” to travel up the limited bandwidth of the nervous system and “crowd out” some of the pain signal coming from the chemical irritation of the eyes. In this case, it could be interference at the level of attention.

If you understand computers, it’s kind of like a DDoS attack plugging up the entrance to “attention” and limiting the access that the pain signal has.

(This is also why you tend to grab onto a painful spot — the neurons responsible for sensing pressure start signaling, and it crowds out the neurons that are emitting pain signal on the limited pathway).